I bought a 1L Effetto Mariposa Caffelatex Sealant (60ml, 250ml and 1000ml × 1) of him (cycleclinic).
I put ~30ml in a front tyre and then snapped the frame of the only bike the wheel was usable on. You're welcome to use some of mine if you want to test it.
I think I need whatever solution he was using. Stan's is shit at high pressure.